<template>
    <div>
        <p>count值为：{{ count }}</p>
        <button @click="add">加n</button>
    </div>
</template>

<script setup>
import { ref } from 'vue';
const emit = defineEmits (['updateCount'])
const count =ref(1)
const add =() =>{
    count.value++
    emit('updateCount',2)
}
</script>